初气厥阴风木。大寒立春雨水惊蛰。二气少阴君火。春厘清明谷雨立夏。三气少阳相火。小满芒种夏至小暑。四气
太阴湿土。大暑立秋处暑白露。五气阳明燥金。秋分寒露霜降立冬。六气太阳寒水。小雪大雪冬至小寒。各至六十日。
显明之右。君火之位也。君火之右。退行一步。相火治之。相火之右。复行一步。土气治之。复行一步。金气治之。
复行一步。水气治之。复行一步。木气治之。（六微旨大论）
六气内经无正文。而于加临明明见之本文者。止有六节气位一章。发明司节之位。而于六节之阴阳上下未之详也。
故后学每以六气一气呼之。又不辨司天六元不同。一概改着。为说以详之。夫天气之行于地。既布之以五行。分之以四
时。历以日月之行。而成岁功。此万古不易。所谓天地合气也。然为气行其间。每不得与日月朔望相齐。故古圣更以斗
杓纪气于十二宫。而祀之以二十四以会周天。后分统以六气。凡六十日以分一气。周而复始。所谓四时之止也。然其为
气上下不同。标本各异。初气为厥阴风木者。一阳也。于卦为复。复在九地之下。正当两阴交尽之时。是以上为厥阴。
下为风木。故风木本阳而标阴也。二气为少阴君火。君火见于卯。所谓显明之位。其时为春厘清明。正三阳出地之时。
乃不名之少阳。而号之为少阴。不名风木。而名以君火者。以此时三阳虽出地。而其上仍属三阴春寒犹属是气。尚为阴
之少。故曰少阴。君火见于此者。易所谓帝出乎震也。帝主十二辰。于时无所不统。而于此分时者。前此一阳尚在九地
之下。而人历于显明。则圣作物睹。是以首出之于此也。其火主照临。不主热物。亦不夺春令。故曰君火不用。君火之
右。即为夏令。为三气之阳相火。相火当巳午为南离君位。非相火之所当。唯君火不用。故退行一步。使相火当之。俾
为夏官。以供臣职。故名以相火。明其无犯上之嫌也。相火当六阳之盛。正为太阳。乃不曰太。而曰少者。以阳虽盛。
而尚在地上。未亢未高。故犹曰少阳也。四气为太阴湿土。湿土在未坤也。坤为太阴。位在未上。又当未月。坤正临事。
故以太阴名之。又其时自大寒一阳生。以及于六阳。为上半年干之行事。自夏至一阴生。至亥以尽于六阴。为下半年坤
之行事。阳以顺行。阴以逆行。故一阴之生。不名一阴。以其生由太阴坤德。故即以太阴名之。时虽溽暑酷烈。六阳极
盛。而总曰太阴者。以阳已退职也。且当此之时。使非土润溽暑。则南离火旺。燥金安生。唯坤居其间。以土合火。而
腾其湿气。则大雨时行。而得以御火。使金气生。而气进与六阳代禅。非太阴之为而谁为耶。五气为阳明燥金。阳明者。
以其时去溽蒸而清明。退蒙昧而 敛。坚洁清肃。阳在上而方明。故曰阳明。金气坚而且洌。是以为燥。六气为太阳寒
水。寒水于时为亥。水属三阴。乃其上为太阳者。此时阳退而在上。为亢为高。在五阴之上。于卦为剥。居停而不用事。
故以太阳名。而纳之寒水也。寒水本阴。而标阳者。以此总之。正六气进气居下。退气居上。春夏阳自下升。故厥阴少
阴在上。秋冬阴亦自下而上。故阳明太阳在上。在下者为进气。在上者为成功。而进退之气。标本之说。于是可见矣。
此为主气司天。所加为客气。主客之分以此。
初之气为厥阴风木。对应大寒、立春、雨水、惊蛰四个节气。二之气为少阴君火。对应春分、清明、谷雨、立夏四个节气。三之气为少阳相火。对应小满、芒种、夏至、小暑四个节气。四之气为太阴湿土。对应大暑、立秋、处暑、白露四个节气。五之气为阳明燥金。对应秋分、寒露、霜降、立冬四个节气。六之气为太阳寒水。对应小雪、大雪、冬至、小寒四个节气。每个气各主六十日。
在显明之右，是君火的方位。君火之右，退行一步，由相火主事。相火之右，复行一步，由土气主事。再复行一步，由金气主事。再复行一步，由水气主事。再复行一步，由木气主事。（出自《素问·六微旨大论》）
《内经》中关于六气的正文已佚，而在加临（客气加于主气之上）的论述中明确可见的原文，仅有“六节藏象论”一章，阐明了司节的方位，但对于六节阴阳上下关系并未详述。因此后学者常将六气混为一谈，又不分辨司天与在泉（六元）的不同，一概随意更改附会，为此我详细阐述其说。天气运行于大地之上，既以五行布列，又以四季区分，历经日月运行而成就岁功。这是万古不变的规律，所谓天地合气。然而气在运行过程中，往往不能与日月朔望完全对齐。所以古代圣人改用北斗斗杓在十二宫的位置来纪气，并以二十四节气来会合周天度数。后来将其统分为六气，每六十日分配给一气，周而复始，这就是所谓的四时之止。然而这些气的上下位置不同，标本各异。初之气为厥阴风木，属于一阳。在卦象上为复卦。复卦位于九地之下，正当两阴交尽之时。所以上面称为厥阴，下面称为风木。因此风木本属阳而标属阴。二之气为少阴君火。君火见于卯位，即所谓显明的方位，此时为春分清明，正是三阳出地之时。却不称之为少阳，而号之为少阴；不称风木，而名以君火，是因为此时虽然三阳出地，但其上仍属三阴，春寒犹存，尚为阴之少，故曰少阴。君火见于此，正如《易经》所说“帝出乎震”。帝主宰十二辰，于时无所不统，而在此分时，前此一阳尚在九地之下，而人历处于显明之位，则圣物显现，因此首出于此。其火主照临，不主热物，也不夺春令，所以说君火不用（指不单独主令）。君火之右，即为夏令，为三之气的阳相火。相火当巳午时为南离君位，并非相火所当之位，唯有君火不用，故退行一步，使相火当之，俾使其成为夏官，以供臣职，故名以相火，表明其无犯上的嫌疑。相火当六阳之盛，正应为太阳，却不叫太而叫少，是因为阳气虽盛，但尚在地上，未亢未高，故仍称为少阳。四之气为太阴湿土。湿土在未坤也。坤为太阴，位在未上，又当未月，坤正临事，故以太阴名之。另外，此时自大寒一阳生，以及于六阳，为上半年乾之行事；自夏至一阴生，至亥以尽于六阴，为下半年坤之行事。阳以顺行，阴以逆行。所以一阴之生，不名一阴，因为其生由太阴坤德，故即以太阴名之。时虽溽暑酷烈，六阳极盛，而总曰太阴者，是因为阳已退职。且当此之时，假使不是土润溽暑，则南离火旺，燥金怎能生成？唯有坤居其间，以土合火，而腾其湿气，则大雨时行，从而得以御火，使金气生，而气进与六阳代禅。如果不是太阴为之，又能是谁呢？五之气为阳明燥金。阳明者，是因为此时去溽蒸而清明，退蒙昧而收敛，坚洁清肃，阳在上而方明，故曰阳明。金气坚而且冽，是以为燥。六之气为太阳寒水。寒水于时为亥。水属三阴，乃其上为太阳者，此时阳退而在上，为亢为高，在五阴之上，于卦为剥卦，居停而不用事，故以太阳名，而纳之寒水。寒水本阴，而标阳者，以此总之。这正是六气进气居下，退气居上。春夏阳自下升，故厥阴、少阴在上；秋冬阴亦自下而上，故阳明、太阳在上。在下者为进气，在上者为成功，而进退之气、标本之说，于此可见矣。此为主气司天，所加为客气。主客之分以此。
The first Qi is Jueyin Wind-Wood (Jueyin Fengmu, Liver/Gallbladder channel associated with wind and wood element). It corresponds to the solar terms Great Cold (Dahan), Beginning of Spring (Lichun), Rain Water (Yushui), and Awakening of Insects (Jingzhe). The second Qi is Shaoyin Ministerial Fire (Shaoyin Junhuo, Heart/Pericardium channel associated with ministerial fire). It corresponds to the solar terms Spring Equinox (Chunfen), Pure Brightness (Qingming), Grain Rain (Guyu), and Beginning of Summer (Lixia). The third Qi is Shaoyang Ministerial Fire (Shaoyang Xianghuo, Sanjiao/Gallbladder channel associated with ministerial fire). It corresponds to the solar terms Grain Full (Guangman), Grain in Ear (Mangzhong), Summer Solstice (Xiazhi), and Minor Heat (Xiaoshu). The fourth Qi is Taiyin Damp-Earth (Taiyin Shitu, Spleen/Stomach channel associated with dampness and earth element). It corresponds to the solar terms Great Heat (Dashu), Beginning of Autumn (Liqiu), End of Heat (Chushu), and White Dew (Bailu). The fifth Qi is Yangming Dry-Metal (Yangming Zaojin, Lung/Large Intestine channel associated with dryness and metal element). It corresponds to the solar terms Autumn Equinox (Qiufen), Cold Dew (Hanlu), Frost’s Descent (Shuangjiang), and Beginning of Winter (Lidong). The sixth Qi is Taiyang Cold-Water (Taiyang Hanshui, Bladder/Kidney channel associated with cold and water element). It corresponds to the solar terms Light Snow (Xiaoxue), Heavy Snow (Daxue), Winter Solstice (Dongzhi), and Minor Cold (Xiaohan). Each Qi governs for sixty days.
To the right of Xianming (the position of the Spring Equinox/Meridian line), is the position of Ministerial Fire (Junhuo). To the right of Ministerial Fire, moving backward one step, Ministerial Fire (Xianghuo) governs. To the right of Ministerial Fire, moving forward one step again, Earth Qi governs. Moving forward one step again, Metal Qi governs. Moving forward one step again, Water Qi governs. Moving forward one step again, Wood Qi governs. (From *Suwen: Treatise on the Subtle Principles of the Six Qi*)
The main text regarding the Six Qi in the *Neijing* (*Huangdi Neijing*) has been lost. However, what is clearly visible in the context of "Linlin" (the superimposition of Guest Qi upon Host Qi) is only found in the chapter "Six Solar Terms and Viscera Manifestations" (*Liujie Cangxiang Lun*), which elucidates the positions of seasonal governance but does not detail the yin-yang upper and lower relationships of the six segments. Therefore, later scholars often refer to the Six Qi as a single entity without distinction, failing to differentiate between Si Tian (Heavenly Sovereign Qi) and Liu Yuan (Six Origins/Yuan Qi), arbitrarily altering interpretations. I provide a detailed exposition here. The movement of Heavenly Qi operates upon the Earth; it is distributed according to the Five Phases (Wuxing), divided by the Four Seasons, and measured by the movements of the sun and moon to accomplish the year's work. This is an unchanging principle since antiquity, known as the combination of Heaven and Earth Qi. However, the movement of Qi within this process often does not align perfectly with the new and full moons of the sun and moon. Thus, ancient sages used the Dipper handle (Doumiao) recording Qi in the twelve palaces to chronicle the seasons, and sacrificed using the Twenty-Four Solar Terms to converge with the celestial sphere. Later, these were unified under the Six Qi, with each Qi assigned sixty days, cycling repeatedly. This is referred to as the cessation of the Four Seasons. Nevertheless, the positions of these Qi differ above and below, and their Biao (Manifestation) and Ben (Root) are distinct.
The First Qi is Jueyin Wind-Wood, representing One Yang. In hexagrams, it corresponds to Fu (Return). Fu is located beneath the nine earth lines, precisely at the time when two yins exhaust themselves. Hence, above it is called Jueyin, and below it is called Wind-Wood. Therefore, Wind-Wood is fundamentally Yang but manifests as Yin. The Second Qi is Shaoyin Ministerial Fire (Junhuo). Junhuo appears at the Mao position, known as the position of Xianming. At this time, during Chunfen and Qingming, it is exactly when Three Yang emerge from the earth. Yet it is not named Shaoyang, but rather Shaoyin; not called Wind-Wood, but named Junhuo. This is because although Three Yang have emerged, the upper region still belongs to Three Yin, and spring cold persists, representing the minority of Yin. Thus, it is called Shaoyin. Junhuo appearing here aligns with the *I Ching* saying, "The Emperor emerges from Zhen." The Emperor commands the twelve earthly branches, governing all times, but specifically at this division, the previous One Yang was still beneath the nine earth lines. When humans traverse the position of Xianming, sacred manifestations appear, hence it leads out from here. Its fire governs illumination, not heat generation, nor does it usurp the spring command; thus it is said that Junhuo does not act independently. To the right of Junhuo is summer, constituting the Third Qi, Yang Ministerial Fire (Xianghuo). Xianghuo, when at Si and Wu hours, occupies the South Li position of the Ruler, which is not the proper station for Xianghuo. Only because Junhuo does not act independently does it retreat one step, allowing Xianghuo to take its place, serving as the Summer Official to fulfill the duties of a minister. Hence it is named Xianghuo, clarifying that it bears no suspicion of offending the superior. Xianghuo corresponds to the peak of Six Yang, which should ideally be Taiyang, yet it is called Shaoyang rather than Tai. This is because although Yang is abundant, it remains on the ground, not yet exalted or high, thus still termed Shaoyang.
The Fourth Qi is Taiyin Damp-Earth. Damp-Earth resides in Wei-Kun. Kun represents Taiyin, positioned at Wei, and coincides with the month of Wei, where Kun is actively governing. Hence it is named Taiyin. Furthermore, from the birth of One Yang at Great Cold until the Six Yang, it constitutes the operations of Qian (Heaven) in the first half of the year. From the birth of One Yin at Summer Solstice until Hai, exhausting the Six Yin, it constitutes the operations of Kun (Earth) in the second half of the year. Yang moves forward (shun), Yin moves backward (ni). Therefore, the birth of One Yin is not named simply "One Yin," because its origin stems from the virtue of Taiyin Kun. Thus, it is directly named Taiyin. Although the time is humid and intensely hot, with Six Yang at their peak, it is collectively called Taiyin because Yang has retired from duty. Moreover, at this time, if it were not for the moistening dampness of Earth, the Fire of South Li would flourish, and how could Dry Metal generate? Only because Kun resides in between, combining Earth with Fire to ascend its dampness, causing heavy rains to fall frequently, thereby controlling the Fire and allowing Metal Qi to generate. This progression allows Qi to advance and alternate with the Six Yang. If not for Taiyin, who would do this?
The Fifth Qi is Yangming Dry-Metal. It is called Yangming because at this time, the humid heat recedes, bringing clarity; obscurity retreats, leading to contraction. It is firm, clean, pure, and solemn. Yang is above and becoming bright, hence called Yangming. Metal Qi is firm and piercing, which constitutes Dryness. The Sixth Qi is Taiyang Cold-Water. Cold-Water corresponds to the hour/month of Hai. Water belongs to Three Yin, yet its upper aspect is Taiyang. At this time, Yang retreats and rises upward, becoming exalted and high, situated above the Five Yins. In hexagrams, it corresponds to Bo (Splitting Apart). It rests and does not act, hence named Taiyang, while being incorporated into Cold-Water. Cold-Water is fundamentally Yin but manifests as Yang. This summarizes the concept. Specifically, the advancing Qi resides below, and the retreating Qi resides above. In Spring and Summer, Yang ascends from below; thus Jueyin and Shaoyin are above. In Autumn and Winter, Yin also ascends from below; thus Yangming and Taiyang are above. What is below is the advancing Qi; what is above is the accomplished Qi. The theories of advancing/retreating Qi and Biao/Ben become evident here. This describes the Host Qi (Zhuqi) governing Heaven; what is superimposed is the Guest Qi (Keqi). The distinction between Host and Guest lies herein.